The Rural Agricultural Development Authority (RADA) is urging onion farmers in Heartease, St Thomas, to take steps to manage the rise in foliar disease affecting their crops.

Foliar disease primarily affects the leaves. These infections are usually caused by fungi, bacteria or viruses, and they interfere with photosynthesis, weaken plant growth, and reduce crop yield and quality.

It can affect the onion plant from active bulbing to near maturity, resulting in leaf damage and uneven bulb sizing.

As a result of recent heavy rainfall, the presence of purple blotch, downy mildew, and Stemphylium blight has been detected mainly in Heartease, but also in parts of St Elizabeth.

Senior RADA Plant Health and Food Safety Officer Francine Webb told JIS News that agency representatives have been on the ground educating farmers on the best approaches, based on prevailing conditions.

She noted that the situation is driven by environmental factors and is not the result of neglect or poor farming practices.

“Disease management is something you do, based on the weather. So, largely, your protectants work well when you have dry conditions. When it is wet, you have to switch and do your chemical rotation, including your systemics, which will be taken up by the plant to help with a more curative action rather than just protecting from the outside as well,” Webb stated.

Meanwhile, acting chief post-entry quarantine officer in the Ministry of Agriculture, Fisheries and Mining’s Research and Development Division at Bodles, St Catherine, Patrice Pitter, emphasised that because of the vital role of the leaf, onion farmers must make every effort to curtail the spread and impact of the disease.

“So the leaf of the plant is where the food is made. Once the leaf is damaged, then you’ll reduce the productivity of the plant. So the onion is grown for its bulb. If we don’t have any leaves there to produce the food, then we will not have any bulb to get for the onion.

“There may be deterioration of the leaves or degradation, and that is because of the moisture level that is there and the pathogen that is present. So it breaks down the cells of the plant and it destroys the leaf… but it can also go down and destroy the bulb,” she explained.

So far, both RADA and the team at Bodles have issued technical advisories to farmers and provided recommendations on the most effective courses of treatment.

With onion plots in Heartease located in very close proximity to each other, farmers are being reminded to ensure that treatment is carried out across all farms through coordinated, area-wide actions.